Utilization of waste hemicelluloses lye for superabsorbent hydrogel synthesis.

A high-performance superabsorbent hydrogel have been successfully fabricated by using waste hemicelluloses lye. Not any extra base was added into the synthesis system for achieving hydrophilic polymer composite. In addition, polyvinyl alcohol (PVA) was added the reaction system to entrap within the hemicelluloses-g-AA/bentonite matrix and form a semi-interpenetrating polymer networks (semi-IPN) for enhancing the swelling properties of the as-prepared polymer composite. SEM, FTIR, and TG were employed to characterize the morphologies, structure, and thermal stability of as-synthesized hydrogel composite. Moreover, liquid absorbency in distilled water and saline solutions, water absorption rate, water retainability, and water reusability of hemicelluloses-g-AA/bentonite (HAB) and hemicelluloses-g-AA/bentonite-PVA (HAB-PVA) hydrogels were also investigated systematically. The adsorption kinetics and isotherms of the composites were studied, and the synergy effect of PVA and bentonite were also proposed. This method provides a new avenue to design the new structure of superabsorbent hydrogel and treat the waste lye in green and sustainable chemical engineering processes.